Fewer than half a million public service workers have gone out on strike, ministers claim, as unions put the figure at more than one million.

Cabinet Office minister Francis Maude said it had been the lowest recorded civil service turnout for a national strike, but pictures showed thousands protesting in the streets of the capital.

Tensions have been running high among the one million teachers, firefighters, civil servants and other public sector workers the unions say are on strike after the Government dismissed the strike as failing.

Striking workers on the streets of London

They have been taking the industrial action in bitter disputes over pay, pensions, jobs and spending cuts.

One in eight schools was estimated to have closed while callers to job centres faced a limited service due to "severe difficulties".

Mr Maude said: "Our official estimates are that fewer than half a million took part in this strike action - well short of the inflated claims of union leaders.

"Within the Civil Service, there has been the lowest recorded turnout for a national strike.

"Every Jobcentre opened, the majority of children went to school as normal and fire services continue to operate with robust contingency arrangements in place."

His department said only around a fifth of civil servants had taken part in the strike, a figure the Public and Commercial Services (PCS) union described as "laughable".

The row over David Cameron's pledge to change the law to make it illegal to strike unless a greater majority of union members voted for action has intensified, with those on strike accusing him of "utter hypocrisy".

Karen Russell, a teacher from Middlesex, told Sky News: "I've just had enough of the Government not listening to the concerns of teachers."

Video:'Why I Am On Strike'

She said taking a day out of school was not disruptive to children - they had been given a day off for the Royal Wedding - and that parents she had spoken to supported the strike.

But mother-of-three Katrina Poole, from Bristol, who has had to make special arrangements for her children, said: "I know teachers work very, very hard, but they've got 13 clear weeks off school and maybe they could deal with this outside educational time."

In Brighton, council worker Corinna Edwards-Colledge said: "I'm really angry when I look around and see my friends - ordinary working people - being scapegoated, and taking the brunt of the cuts.

Video:Firefighters Join Mass Strike

"Then I hear that the richest people have seen their wealth increase by 14% in the last year alone, when I have friends who are having to miss meals."

The PCS union described those figures as "laughable".

In March, the Government announced a 1% pay rise for public sector workers. However, Office for National Statistics figures show that public sector workers earn, on average, 14.5% more than those in the private sector.